"Wiimote 1 disconnected by emulated software"

[thedevilsjester]

I have the same (or similar) problem using a Real (official) Wiimote with the DolphinBar.

After a lot of trial and error and finding out that if I ran dolphin-emu with root permissions, it just worked, I found this:
https://forums.dolphin-emu.org/Thread-dolphinbar-ubuntu-16-04?pid=438745#pid438745

That works perfectly and lets non-root users run dolphin-emu and have access to the DolphinBar.  You might need similar rules for whatever devices you are using for Dolphin